If you happen to like the color purple then surely you have a lot of stuff in purple particularly in your home. This color is so bright and cheerful it would make a good color base for the bathroom. If you want a splash of color in your shower, buy a purple shower curtain.
Your curtain is a good place to start with your color scheme, since when stretched out, it is one of the biggest space or area in the bathroom. It is almost as wide as your wall. There are many options for this color. You can choose one in a single color. It will be very strong when matched with a contrast color like lime green, white, or even aqua blue. Or if you want more color options, you can purchase one in stripes or prints with two or more colors. That way you would not be stuck in a single color, you can use elements of these colors for your other accessories.
A purple shower curtain with yellow and pink stripes for instance can be fun to work with. You can purchase a pink trash can matching the exact shade of pink in the curtain. Or you can have all your towels in yellow, so that they look nice when stacked on the shelves. You can also have combinations of pink and yellow soap case, toothbrush holder, glass and so on for your bathroom mirror. The key is to stick to the color scheme and little by little, build up your bathroom decoration.